Rifle bullets have a conventional elongate shape with pointed tip. The elongate shape adds stability during flight and increases the kinetic energy for a particular bullet size. The elongate shape also increases metal surface area contacting the metal barrel during firing and the metal to metal, barrel to bullet, friction can reduce the muzzle velocity of the bullet. Bullets are known having rearward ends with a boat tail and circumferential grooves, both of which have the effect of reducing the surface area of elongate bullet and the metal to metal engagement and friction. Such grooves in rifle bullets have previously been filled with grease for lubrication between the barrel and bullet. Bullets with grooves filled with grease are not commercially feasible in today's market.
Innovations providing even incremental improved performance of bullets would be welcome in the marketplace. Such improved performance would certainly include increasing the muzzle velocity of a bullet without effecting its ballistic coefficient. Providing such improved performance with minimal increase in manufacturing cost would be very advantageous.